JPH1093488A - Self-test transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To verify whether or not equipment is operated normally by transmitting a self-test signal to be received through at least one of a first and a second receiver path by a transmitter and receiving the self-test signal by a receiver. SOLUTION: An intelligent radio port IRP unit 10 contains a transceiver module 12 and the module is connected to a digital control module 14. The module 12 is a single substrate transceiver and constitutes a part of the IRP unit 10. Main functions of the module 12 are to transmit/receive a control signal and an information signal of digitally modulated radio frequency to/from mobile radio communication device. The transceiver responds to the signal generated from a module 14 and waits for an incorporated test circuit to test the transceiver itself. Additionally, the transceiver 12 has function which detects an interference signal of the radio frequency from other IRP and consequently, generates an adjacent lists of radio ports near the IRPs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates generally to the field of radio frequency transceivers, and more particularly, to radio frequency transceivers incorporating self-test functionality.

[0002]

One application of the use of radio frequency (RF) transceivers is in transmitting and receiving RF signals for radio ports used in wireless communication systems. These radio frequency transceivers, which have been improved for the use of radio ports in today's radio communication systems, are not integrated units in performing certain important functions. Important functions, such as, for example, transceiver self-tests, are performed by various other external hardware components. In addition, these other external components may be used to measure the radio channel in use by other nearby radio ports and to build a neighbor list of radio ports. This reliance on external components used in connection with today's transceivers increases the complexity of the interface between the transceiver and the external components, and adds to the design cost due to the use of the external components themselves. Cause. Such a design also increases the chances of the radio port failing, and therefore, the maintenance costs are high.

[0003] Thus, a fully integrated, internally performing independent transceiver function such as self-test and measurement of active radio channels from other radio transceivers without relying on other external components. There is a need for a dedicated transceiver unit.

[0004]

SUMMARY OF THE INVENTION In accordance with the present invention, a one-piece diversity receiver and transmitter capable of performing a self-test operation to determine whether the receiver and transmitter paths are operating properly. SUMMARY An integrated radio frequency transceiver is disclosed. This diversity receiver includes two receiver paths, but the first path is used to receive wireless communications with allowed bandpass and the second receiver path is Used to receive radio signals from transceivers.

[0005] The transmitter portion includes a quadrature modulator, which is modified to receive local oscillator signals from a certain frequency synthesizer and a certain intermediate frequency synthesizer to generate an appropriate transmit frequency. The transmission path of the transmitter section can be switched between the second receiver path and the transmission / reception via a band-pass filter. The frequency synthesizer also provides a local oscillator signal for a mixing process in the first receiver path. The first receiver path section, which includes two parallel bandpass paths for receiving two frequency ranges, also receives a local oscillator signal from the frequency synthesizer for mixing with the incoming signal.

For self-stating purposes, the transmitter part is:
Modified to transmit a test signal, which is routed to each receiver path by an internal switch. Successful reception of the test signal indicates that the transmitter and receiver paths are functioning properly. The second alternative receiver path allows the radio frequency transceiver to detect radio signals from other frequency transceivers in the radio communication system and maintain a list of active radio frequency transceivers.

[0007] A more complete understanding of the present invention may be obtained by considering the following description in conjunction with the drawings.

[0008]

1 is a schematic block diagram of a module of an intelligent wireless port (IRP) unit according to the present invention. As shown, the IRP unit includes a transceiver module 12, which comprises:
Coupled to the digital control module 14. As will be appreciated by those skilled in the art, in the embodiment shown, the transceiver module 12 is a single-board transceiver, which forms part of the Intelligent Radio Port (IRP) unit 10. The primary function of transceiver module 12 is to transmit and receive digitally modulated radio frequency (RF) control and information signals to and from a mobile wireless communication device. As will be described, the transceiver has a built-in test circuit for testing itself in response to signals generated from the digital control module 14. In addition, the transceiver 12 is connected to another intelligent wireless port (IR
P) has the ability to detect, or sniff, radio frequency interference signals, thereby creating a neighbor list of these nearby wireless ports.

FIG. 2 shows the transceiver 12 as an RF circuit module that forms part of an intelligent wireless port of a wireless communication system. In one preferred embodiment, the transceiver is capable of transmitting in the 869 to 894 MHz band and receiving in either the 824 to 849 MHz band or the 869 to 894 MHz band.
However, as will be appreciated by those skilled in the art, other bands may be utilized. The various operational features of the transceiver allow the device to function in the following functional modes: transmitter mode, diversity receiver mode, synthesizer mode, self-test mode, and sniffing mode;
Each of these modes is described in detail below.

In the following description, reference will only be made to the processing of radio frequency signals performed by transceiver 12 of the present invention. The digital control portion of the transceiver is provided by a digital control module (shown in FIG. 1), which is modified to interface with transceiver module 12, as will be appreciated by those skilled in the art. All signals except the two RF signals interface directly to this digital control module board.

Continuing with FIG. 2, the transmitter portion of the transceiver of the present invention includes a quadrature modulator 20, which comprises:
For example, operating at 5.0 volts, about -3 dBm (deci
belsbelow 1 milliwatt) of power output. Quadrature modulation, the modulation of two carrier components 90 ° out of phase by separate modulation functions, is well known to those skilled in the art. In the context of the present invention, these modulated signals are referred to as IIN and QIN signals for transmission operations,
For the reception operation, IOUT / I1OUT and QOUT / Q
Referenced as 1 OUT signal. Right Angle Modulator 20 of the Present Invention
Includes a built-in power control whereby the output power is attenuated by about 50 dB. By using a complementary metal oxide semiconductor / transistor transistor logic (CMOS / TTL) compatible input, the device enters a power down mode if less than 10 microamps of supply current is being consumed. As the quadrature modulator of the present invention, for example, a single chip integrated circuit package model No. provided by AT & T Corp. W201
1 can be used.

In the embodiment shown in FIG. 2, the quadrature modulator 20 is a direct conversion modulator with an internal offset mixer to prevent the outer voltage controlled oscillator (VCO) from being pulled down by large transmit signals. Is used. This transmitter section requires a low level local oscillator (LO) signal so that no amplifier is used on the synthesizer. The transmitter section receives one 82.2 MHz LO signal from an intermediate frequency (IF) synthesizer 24 via a three-way splitter 22. This transmitter part also has another 745-
A 770 MHz or 787-811 MHz LO signal is received from the agile frequency synthesizers 26, 28 based on the transmit frequency, thereby allowing the upper sideband output to generate the desired frequency. . As you can see from the figure, Agile Synthesizer 2
The LO signals from 6, 28 are connected to resistive splitters 30, 3,
2. Arrives via fixed attenuator 34, SPDT switch 36, and low-pass filter 38. The use of frequency synthesizers to provide multiple frequency outputs is well known to those skilled in the art. As can be appreciated, the agile frequency synthesizers 26, 28 utilized herein are programmed and controlled by a processor, eg, a microprocessor (not shown), to provide the desired L.
Obtain the O signal.

In one preferred embodiment of the present invention, the output from quadrature modulator 20 is the output of first stage amplifier 4.
Although input to 0, amplifier 40 boosts this output signal by a certain amount, for example, 18 dB. The output of this amplifier 40 enters the last power amplifier stage, which
Add another 7 dB of gain to this signal. The output of amplifier 40 then enters a -15 dB directional coupler 42 to monitor the power output to antenna 44. That is,
Bandpass filter (BPF) duplexer 46 and S
After passing through the PDT switch 48, the power signal IIN / QIN thus processed is directed to the antenna 44,
Radiated from here. The SPDT switch 48 sets this R
The F power is directed to the antenna 44 or to another receiver path for a loopback test, as described below.

In the intelligent radio port used with the integrated transceiver 12 of the present invention, the transmitter power can be reduced in 4 dB steps from the maximum rated transmitter power that the transceiver can transmit. Needed. To achieve a flat characteristic independent of gain spread within the amplifier stage, a power smoothing loop, including a power detector 50, external to the amplifier 40 is used. The output of the transmitter is adjusted by changing the control voltage directed to the gain control input of the transmitter. This DC control signal is generated by low-pass filtering a pulse width modulated (PWM) signal from a microcontroller in the power detector. The transmitter is thus measured by using the outer power meter to find the corresponding PWM number for each power level. However, one problem is that the power output also fluctuates with a small change in the gain or load impedance.
However, if accidentally removed from the operating unit, the unit may be damaged by reverse power. To solve this problem, a reverse power is detected and rectified by a power feedback loop provided in the -15 dB directional coupler 42. In effect, this signal is added to the DC control signal output from the microcontroller. Thus, the loop settles out so that the output of the detector diode in the directional coupler 42 is equal to the reference level. This reference level is derived directly from the microcontroller and is set according to the desired output power.

As can be appreciated, for the purpose of self-test, it should be appreciated that the transmitter is 824-896M
Hz, but the input to the band-pass filter (BPF) transmission / reception switch 46 is from 869 to 894 MHz.
Only frequencies of z are accepted, which results in signal losses as high as 60 dB. Therefore, for calibration of each transceiver unit, it is necessary to find the exact signal arriving at the receiver. Also, the channel used to perform the self-test should preferably be a channel not used by the mobile wireless communication device.

In connection with the diversity receiving function of transceiver 12, a receiver portion receives digitally modulated RF control signals and information signals from the mobile radio communication device and converts the baseband signals to a baseband processing unit. Understand to send. The receiver part is -15
signal from dBm to -102 dBm or 87d
Handles the dynamic range of the BM. The receiver portion uses a double heterodyne approach within each receive channel. That is, one at the mixers 51, 52 and the other at the receiver IF subsystems 53, 54.
Each refers to two mixing processes. One uses 82.2 MHz from the agile frequency synthesizers 26 and 28 and the IF synthesizer 24, and the other uses two intermediate frequencies of 455 kHz. These intermediate frequencies from the agile frequency synthesizers 26, 28 are transmitted from the resistive splitters 30, 32,
The signal passes through the switch 21, the amplifier 23, the splitter 25 and the amplifier 27 to the mixer 51, or to the mixer 52 via the amplifier 29. The local oscillator source for the 455 kHz frequency is derived from a 1.82 MHz crystal oscillator 56, which is frequency divided by a frequency divider 58 and input to the receiver IF subsystem.

The diversity receiver part consists of two identical receivers, a first receiver RX0 and a second receiver RX1. Both RX0 and RX1 include an RF amplification circuit, a down conversion circuit, an IF band-pass filtering circuit, an IF amplification circuit, a gain control circuit, a demodulation circuit, and a baseband circuit. As can be seen, the RX0 and RX1 receivers both include similar components. More specifically, the RX0 path is transmitted from the antenna 60 via the BPF 61 to the LNA 63 and the BPF
65, or via BPF 62, LNA6
4. BPF 66, then SPDT switch 6
8, mixer 51, IF filter 70, IF filter 73
Including a receiver IF subsystem 53 cooperating with IOUT
And a QOUT signal. On the other hand, the RX1 path, more specifically, the antenna 44, the SPDT switch 48,
It includes a BPF duplexer 46, LNA 74, BPF 76, mixer 52, IF filter 31, and receiver IF subsystem 54 cooperating with IF filter 79 to provide I1OUT and Q1OUT signals.

With respect to the RX0 receiver portion, the RF amplifier circuit includes a four-way switch 80, which converts the received signal into an appropriate receive path bandpass filter (BP).
F), ie, 869-894 (MHz), respectively.
Alternatively, it is connected to 824-849 (MHz). This switch 80 also routes the self-test signal from the transmitter section to the 869-894 MHz bandpass filter 61. These signals have a low noise amplifier (LNA) 64 with a typical noise figure of about 3 dB, or about 2.
It is amplified by the LNA 63 having a noise figure of 5 dB and routed to the mixer 51 by the SPDT switch 68. As will be appreciated by those skilled in the art, LNA
64 has a 1 dB compression point of 21 dBm and handles high level band B signals without saturating the amplifier.

The down converter circuit of the RX0 receiver section is as follows:
It includes a double balanced mixer 51, which combines the incoming received signal from the RF amplifier circuit with the agile LO frequency to produce a first IF of 82.2 MHz. The second mixer in the IF subsystem 53 uses the 82.2 MHz
Of the 82.2 from IF synthesizer 24
Combined with the LO frequency of MHz to produce a third IF of 455 kHz. Finally, this 455 kHz signal is
Mixed with a fixed 455 kHz LO frequency, I
out and Qout signals are generated.

The IF bandpass filter 70 of the RX0 receiver provides a channel separation function for this receiver. In the example shown here, the 3 dB bandwidth of this filter is 30 kHz. As will be appreciated by those skilled in the art, the filter 70 passes the tuned channel and rejects all other channels. The first I
The F filter 70 is an 82.2 MHz surface acoustic wave filter and requires input / output matching to 50 ohms. The other IF band pass filter 73 is 455 kHz
And 3d at 28 kHz and 20 kHz, respectively.
B bandwidth. The filter 73 is preferably a ceramic filter, which has a low group delay response and a nominal impedance of 100
It ranges from 0 ohms to 1500 ohms.

The receiver IF subsystem 53 has a low power I
F subsystem, a 500 MHz high first I
It operates at the F frequency and a second IF frequency at a height of 22 MHz. Subsystem 53 preferably includes a mixer, an IF amplifier, I and Q demodulators, a phase locked quadrature oscillator, an automatic gain control (AGC) detector, and a bias system with external power down. In one preferred embodiment, this subsystem includes Anal
An AD607 single chip IC available from og Devices, Inc. is used. This IF subsystem part includes a low noise, high cutoff input mixer, which is a double balanced Gilb
It is of the ert-Cell type and operates linearly for RF inputs ranging from -102 to -15 dBm. The mixer section also includes a local oscillator preamplifier, which reduces the drive (signal) to -16 dBm. This single sideband IF output can directly drive a bandpass filter with an impedance of 200 ohms or more. The gain control input is treated as either a manual gain input or as an automatic gain control voltage-based radio signal strength indicator (RSSI) output.

Diversity receiver path RX1 is similar to receiver path RX0, except that 2-way SPDT switch 48 routes the transmit signal to antenna 44 or to the RX0 receiver path for self-test. What you can do is different. The BPF-based duplexer 46
Provides isolation between the transmit and receive paths.

As shown in FIG. 2, the synthesizer functional group of the transceiver 12 of the present invention is 82.2 MH.
from the agile IF synthesizer 24 that provides the LO source of z, a fixed 1.82 MHz crystal oscillator 56 (by dividing this frequency by a quarter to obtain a 455 kHz signal), and two frequency agile synthesizers 26, 28 Be composed. All three of these synthesizers 24, 26 and 28 are programmed,
The output from these frequency synthesizers is controlled by a microprocessor (not shown).
Coherently locked to a MHz reference frequency. The chips used for phase locked loop (PLL) operation are preferably National Semiconductor Corp.
The LMX 2332 from is used. It has a dual synthesizer that includes a prescaler. Each chip is used to generate one RF and one IF local oscillator signal. Since a transceiver is required to transmit in two different bands and receive in two different bands, at least four phase locked loops (PLLs) are required when using a direct up-conversion transmitter. While required, on the other hand, in the embodiment shown, an offset transmitter is used, so that two RF
Only a local oscillator is needed.

As mentioned above, the transceiver 12 of the present invention can also operate in a self-test mode, in which the receiver essentially has its own central processing unit on the digital control module. Tests with commands from to find failed elements in the transmit or receive path. The transmitter sends a test signal, eg, 8
Transmit a specially encoded message of 24-849 MHz, which is routed by SPDT switch 48 to both receiver portions RX0 and RX1. At a separate port of the digital control module for each receiver portion, if the processing unit detects that this test signal has been successfully received, the transceiver 12
It can be seen that the transmission and reception paths within are operating normally. The output of the duplexer filter 46 at the transmitter is 869-894 MHz.
Still, it passes the test signal with about 60 dB of attenuation,
This is sufficient for testing purposes. Another unique feature of the present invention is that the transmitted signal is generated by heterodyning the receiver local oscillator (the signal) and the 82.2 MHz IF signal, thereby allowing the two synthesizers Use is eliminated.

The receiver portion of the present invention can also detect radio interference signals from other intelligent radio ports (IRPs) by operating in the sniffing mode. The SPDT switch 48 is connected to another intelligent wireless port (I
RP) is received by an alternate receiver path R
It has a function to route to X1. Based on this signal received at the control module, each intelligent wireless port (IR
P) maintains a list of nearby active IRPs,
This is recorded in the memory in the control module. Since these signals from the other intelligent radio ports (IRPs) are not very large, the low noise amplifier 74 used in this path can have a low 1 dB compression point, and therefore a suitable low noise amplifier Is used.

From the above description, it is to be understood that the embodiments described in connection with the drawings are exemplary only, and that those skilled in the art will appreciate that various modifications to the illustrated embodiments can be made without departing from the spirit and scope of the invention. And that modifications are possible. All such variations and modifications are to be understood as falling within the scope of the invention, which is defined by the following claims.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing one embodiment of an intelligent wireless port according to the present invention.

FIG. 2 is a schematic block diagram of one embodiment of an integrated transceiver module according to the present invention.

Claims (20)

[Claims] 1. An integrated radio frequency transceiver device improved for use with a radio port utilized for communication in a wireless communication system, the device comprising: a given frequency band. A transmitter capable of transmitting radio frequencies within a given frequency band; and a diversity receiver having first and second receiver paths for receiving radio frequencies within a given frequency band, said transmitter comprising: Responds to the self-test command
Having a function of transmitting a self-test signal to be received through at least one of the first and second receiver paths, wherein receiving the self-test signal from the at least one receiver path; Verifying that the transmitter and the at least one receiver path are operating properly. 2. A digital control module coupled to the transmitter and the receiver, the digital control module generating the self-test command and generating the self-test signal. The apparatus of claim 1, wherein the apparatus performs a receiving operation. 3. The at least two receiver paths,
A first receiver path for receiving communication signals directed to said wireless port and a second receiver path for receiving communication signals transmitted from transceivers of other wireless ports, The apparatus of claim 1, wherein the neighbor list of the other wireless port is maintained based on receiving a communication signal destined for the other wireless port. 4. The transmitter and the second receiving path are coupled to a combination of a band-pass filter duplexer and a switch, and the combination of the duplexer and the switch is used to simply transmit a communication signal. The apparatus of claim 3, wherein the apparatus is enabled to transmit and receive over one transmit / receive channel. 5. The diversity receiver further comprising:
A frequency synthesizer; and a heterodyne mixer coupled to the frequency synthesizer, the frequency synthesizer providing a local oscillator signal to the heterodyne mixer, whereby the radio frequency in the diversity receiver is reduced. The device of claim 1, wherein the device is generated. 6. The transmitter according to claim 1, further comprising a quadrature modulator, wherein the frequency synthesizer further supplies a local oscillator signal to the quadrature modulator, whereby the quadrature modulator is provided in the transmitter. The apparatus of claim 5, wherein a radio frequency is generated. 7. The transmitter further includes an intermediate frequency synthesizer, which provides a local oscillator signal to the quadrature modulator, thereby generating the radio frequency in the transmitter. The apparatus of claim 6, wherein 8. The diversity receiver further comprises:
The apparatus of claim 7, including an intermediate frequency receiver subsystem, wherein said intermediate frequency synthesizer further provides a local oscillator signal to said intermediate frequency receiver subsystem in said diversity receiver. . 9. The quadrature modulator for modulating the communication signal generated from the transceiver, the transmitter further comprising a quadrature modulator coupled to the quadrature modulator. A directional coupler and a power detector, which provide a power smoothing loop for the signal transmitted from the transceiver, the power smoothing loop for the transmitted signal: The apparatus of claim 1 operative to produce a flat transmission characteristic independent of the gain spread of an associated amplifier stage. 10. The power detector generates a pulse width modulation (PWM) control signal, which is input to a gain control input of the transmitter, and thus is transmitted by the gain control input. The apparatus of claim 9, wherein the output of the machine is adjusted in response to said control signal. 11. The directional coupler is modified to detect a reverse power signal input thereto and rectify the reverse power input signal, wherein the rectified reverse power The apparatus of claim 9, wherein an input signal is added to said PWM control signal. 12. The first receiver path includes first and second sub-paths, wherein the first sub-path receives a radio frequency signal in a first predetermined passband. Wherein the second subpath includes one or more bandpass filters for receiving radio frequency signals in a second predetermined passband. The apparatus of claim 1 wherein: 13. The apparatus of claim 12, wherein said first passband is in the range of 824 to 849 MHz and said second passband is in the range of 869 to 894 MHz. 14. Within the diversity receiver, further includes an intermediate frequency receiver subsystem for providing a second stage heterodyne mixing process, whereby the intermediate frequency receiver subsystem within the given frequency band is provided. The apparatus of claim 1, wherein a radio frequency is generated. 15. The intermediate frequency receiver subsystem is utilized in the at least two receiver paths of the diversity receiver, wherein a first path is directed to the wireless port. 15. The apparatus of claim 14, wherein the apparatus is used to receive wireless communications, and an alternative receiver path is used to detect wireless signals transmitted by other radio frequency transceivers. 16. The digital control module of claim 2, wherein said self-test signals for said first and second receiver paths are received at separate corresponding ports of said digital control module. apparatus. 17. An integrated radio frequency transceiver device improved for use with a radio port utilized for communication within a wireless communication system, the device comprising: a given frequency band. A transmitter capable of transmitting a radio frequency within a given frequency band; and a diversity receiver for receiving a radio frequency within a given frequency band, said transmitter responsive to a self-test command to Performing an operation of transmitting a self-test signal to be received at one receiver path, and receiving the test signal verifies that the operation of the transmitter and the receiver path is normal. An apparatus characterized in that: 18. A digital control module coupled to the transmitter and the receiver, the digital control module generating the self-test command and the self-test. The apparatus of claim 17 having a function of receiving a signal. 19. The diversity receiver includes a second receiver path, wherein the first receiver path is used to receive a communication signal destined for the wireless port; Is used to receive the communication signal transmitted from the transceiver of the other radio port, whereby the neighbor list of the other radio port is used for receiving the communication signal from the transceiver of the other radio port. 18. The apparatus of claim 17, wherein the apparatus is maintained based on receiving a communication signal. 20. The self-test signal can be generated toward the second receiver path, and the stet signal for each receiver path is a separate port of the digital control module. 19. The device of claim 18, wherein the device is received at: